J16 Mr. Asprtty on a Mach 
Now it is found that when this injur¬ 
ed grain, especially wheat, is reduced 
to flour and made into bread, the bread 
is very sad and heavy : a property un¬ 
congenial to the sale of the bread, as 
well as to individuals’ stomachs. The 
reason of this appears to be, that good 
wheat flour, which by vegetable ana¬ 
lysis yields principally gluten and 
starch, loses by germination the quality 
of the starch, which is converted iuto a 
saccharine matter for the nourishment 
of the young sprouting plant, and hence 
the spongy lightness of which starch is 
known to be the cause, ceases on ac¬ 
count of the change which vegetation 
has effected in it. 
Now it must seem evident that, if 
from among the tuberose roots which 
afford farina in considerable quantity, 
and which the season cannot have in¬ 
jured, but rather must have conduced 
to their finer growth, we can select 
one which yields starch largely, it 
will be our advantage to decide on it; 
and as the potatoe is extensively culti¬ 
vated for culinary purposes, as well as 
composed of a principal ratio of starch, 
so for many other reasons it seems the 
best. 
Accordingly, it has been found that, if 
potatoes be reduced to pulp, by grating, 
be worked in cold water, and then if the 
liquid be strained through a hair-sieve, 
to separate the parenchyma, and be al¬ 
lowed to remain quiet for a short lime, 
the starch which is first diffused through 
the fluid, will gradually subside to the 
bottom of the vessel, and there settle 
so firmly as almost to resist the inden¬ 
tation of the finger ; if the supernatant 
liquor be now poured off, and the se¬ 
diment be dried by the air or domestic 
fire, on bibulous paper, it is found to be a 
very fine, white, crystalline starch. If 
this be mingled in the proportion of one- 
fourth to three-fourths of flour, injured 
by growth, and made into dough and 
baked, the resulting bread will be found 
not only tolerably good, but possessing 
the porous consistence to the same de¬ 
gree as ordinary and good bread, the 
addition of starch supplying the loss 
which germination had occasioned. 
As grating with the hand is found to 
be particularly slow and operose, as 
well as giving occasion to the infliction 
of numerous wounds to the hands from 
the hand frequently coming in contact 
with the acuminations of the grater, a 
machine lias been devised, consisting 
ne for Grinding Potatoes. [Jan. 1, 
of a trough elevated on four supports, 
and left open at the bottom for the re¬ 
volution of a solid cylinder, with nu¬ 
merous tin grating projections, which 
covers the whole bottom of the trough. 
The cylinder atone end is turned by 
means of a handle, with a fly-wlieel 
placed at the other to regulate the mo¬ 
tion of the man who turns it : now 
the potatoes by their weight are more 
closely applied to the acuminated cy¬ 
linder, which presents a large grating 
surface, and which forces down the pulp 
between the edge of the trough and the 
cyliuder, into a tray set underneath 
and filled with cold water. 
If the potatoes be already washed 
and near at hand, two men with this 
machine can grind a bushel of potatoes, 
weight about oGlbs. in a quarter of an 
hour, which is said to yield seven pounds 
of starch, this will be 28 pounds in one 
hour. Now, supposing these men to 
work without hindrance for ten hours 
in the day, they would produce 280 
pounds of farina in this time; however, 
it must here be noticed that this state¬ 
ment supposes a handle at eacli end 
instead of a fly-wheel, that two men 
may work. Potatoes are obtained here 
at one shilling per bushel; one-eighth 
of the weight of potatoes is starch. 
I am well aware that it is a common 
practice with some to introduce into 
bread a certain quantity of potatoes, 
that is, of the whole constituents of the 
potatoe: but the addition of starch or 
potatoe-flour seems far less objection¬ 
able, as adding nothing which good 
flour should not contain; namely, 
none of the fibrous matter or albumen 
which enter into the composition of 
potatoe. 
Since the harvest was generally bad 
this year, I conceive the plan here re¬ 
commended as likely to be of some use 
to the agriculturist and baker. 
Thomas Aspray. 
Olneiji Nov. 30 th, 1821. 
P.S. The model of the machine which 
has been constructed in Olney, and which 
has been worked a good deal, is to be found 
in the first volume of the last Supplement 
of the Encyclopaedia Britannica, which if 
it meet the approbation of the editor, the 
writer of this brief article would like to 
see represented in a wood-cut accompany¬ 
ing the paper; however, this is hinted with 
extreme deference to the judgment of the 
editor. — See Monthly Magazine , May y 
1817, p. 340. 
ORIGINAL 
